Winding and spooling devices for extensible materials have presented a problem in packaging a predetermined or accurately measured length of material on the package. The tension required to produce a good package often causes the material to be stretched and therefore distorts the measurements of length. Some elastic products, and for example lace fabrics in particular, are very expensive, and accurate measurement of the material on each package is most desirable.
The present invention aids in winding by feeding the extensible materials and winding them with a minimum amount of tension. This is accomplished by the use of a controlled loop of material being fed across a low inertia measuring device just prior to being wound onto a package. A photocell or other means is used to monitor the position of the material in the loop and control the speed of the winding device to maintain a tension-free package.
Accordingly, it is an important object of this invention to provide apparatus for winding elongated elastic material wherein the elastic fabric and the like is fed in a substantially tensionless state in a winder.
Another important object of this invention is to package elastic fabric and the like upon a winder in such a way that a cosmetically acceptable package is formed without stretching of the material and so that the material is wound and configured in the package in a substantially tensionless state.
Another important object of this invention is to accurately measure a length of elastic material without imparting tension to it in such a way that a more acceptable package may be formed and wherein the correct amount of product may be measured and applied to a given package.
Another important object of this invention is to provide automatic braking for use with the low inertia measuring device to avoid inaccuracies.
Still another important object of this invention is the provision of an adjustable traversing device to allow the winder to be used either as a blocker or as a spooling machine for narrow fabrics to provide a variety of packages.
The prior art includes loop control mechanism of the type illustrated in U.S. Pat. Nos: 2,108,410, 2,379,132, and 3,550,828.